The present invention relates to gas turbine engines, and more particularly, to bearing compartments of gas turbine engines.
The rotating shafts and other rotating turbomachinery of gas turbine engines are supported from a non-rotating structure by arrays of anti-friction bearings. In many engines, the anti-friction bearings are enclosed in bearing compartments that circumscribe the engine shafts. A lubricant such as oil is supplied to the bearing compartments to lubricate and cool the anti-friction bearings during operation of the gas turbine engine. The bearing compartments act to contain the lubricant around the bearings.
To prevent overheating of the rotating shafts, a cooling gas is circulated in the volume between the shafts. An intershaft seal assembly is positioned in the bearing compartment at a gap between the shafts and prevents the cooling gas from leaking from between the shafts into the lubricant supplied portions of the bearing compartments. The intershaft seal additionally prevents the lubricant from leaking into the volume between the shafts.
Carbon seals that make up portions of the inter-shaft seal assembly are retained within the bearing compartment by a carbon seal housing, which in turn is connected to other housings within the bearing compartment. To meet structural integrity requirements, the carbon seal housing uses rigid integral linkages to provide this connection. However, having integral linkages makes installation and removal of the inter-shaft seal assembly including the carbon seal housing impractical or impossible in the bearing compartments of some aircraft due to the tight bearing envelopes necessitated by the aircraft's design criteria.